Question 1
(1) Figure 1 shows an equilateral triangular pyramid in first angle projection, cut along plane Y-Y.
(b) Draw the:
(i) end view in the direction of arrow F;
(ii) complete plan;
(iii) true shape of the cute surface.
Observation
Candidates were able to satisfactorily copy the given views, as asked in (a), and draw the end view in the direction of arrow F, as asked in (b)(i). Their responses to other parts of this question, however, were inadequate. The solution of the entire question and the explanation to the poorly answered part of the question is given below .
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(b) (ii) MAJOR STEPTS TAKEN TO DRAW A COMPLETE PLAN
Projecting down from the cutting plane to plan
Drawing a horizontal line X1 Y1 through point O
Locating points a and b on the lines OA and OB respectively
Locating point C on line OC on plan
Joining the points a, b and c to complete the cut surface
Sectioning the cut surface on the plan
(iii) MAJOR STEPS IN DRAWING TRUE SHAPE OF THE CUT SURFACE
Projecting perpendicular lines from points a1, b1 and c1 on the cutting plane
Drawing a reference line X2 Y2 parallel to the cutting plane Y-Y
Transferring corresponding vertical ordinates of the cut surface from X1 Y1on plan to X2 Y2
Joining the points (a3, b3 and c3) to draw the true shape
Sectioning